Right and left ventricular cardiovascular function will be studied in patients with congenital heart disease using videoroentgenographic techniques. These studies will provide new data on both right and left ventricular segmental contraction as well as "continuous" filling and contraction patterns in various patient groups in which preliminary data have indicated abnormalities of ventricular function. Videodensitometry techniques will be used to develop new methods for right and left ventricular volume determinations which are independent of chamber shape and thus theoretically more accurate than current geometric methods particularly in chambers in which hemodynamic alterations have produced very abnormal chamber shape. Videodensitometry also will be used to quantify systemic and pulmonary blood flow rapidly without the need for blood sampling or arterial cannulation. This technique also will be applied to both right-to-left and left-to-right shunt quantification and valvular regurgitation. These videodensitometry techniques are of major importance in catheterization laboratory evaluation of congenital heart disease because they can provide the following data within minutes following catheter introduction without blood sampling, without arterial cannulation, and potentially with only fluoroscopic radiation and small amounts of contrast media: ventricular and atrial volumes, ejection fraction, systemic blood flow, right and left pulmonary artery flow regardless of whether the pulmonary artery arises from the heart or from the aorta, right-to-left shunt, left-to-right shunt and valvular regurgitation. It is projected that a system to provide these measurements can be developed during the time period of this proposal which could be easily duplicated in most catheterization laboratories with only minor alterations or additions to existing equipment.